Samples of sediments and the overlying water were collected in the Qi＇ao Island coastal zone,the Zhujiang（Pearl River） Estuary（ZE）.Denitrification rates,sediment oxygen demand（SOD）,and fluxes of inorganic nitro...Samples of sediments and the overlying water were collected in the Qi＇ao Island coastal zone,the Zhujiang（Pearl River） Estuary（ZE）.Denitrification rates,sediment oxygen demand（SOD）,and fluxes of inorganic nitrogen compounds were investigated with N2 flux method,using a self-designed continuous flow through and auto-sampling system.The results indicate that the denitrification rates varied between 222 and 908 μmol/（m2·h） with an average of 499 μmol /（m2·h）.During incubation,the sediments absorbed dissolved oxygen in the overlying water with SOD ranging from 300 to 2 363 μmol/（m2·h）.The denitrification rates were highly correlated with the SOD（r2=0.77） regardless of the NO-3＋NO-2 concentrations in the overlying water,organic carbon contents in sediments and water temperature,suggesting that the SOD was probably the main environmental factor controlling the denitrification in the Qi＇ao Island coastal zone.There was a net flux of NO-3＋NO-2 into the sediments from the overlying water.The NH＋4 flux from sediments into water as the result of mineralization was between 12.3 and 210.3 μmol/（m2·h）,which seems limited by both organic carbon content in sediment and dissolved oxygen concentration in the overlying water.展开更多
Compared with marine facies shale strata,lacustrine shale strata are more complicated in geological conditions,and thus more difficult to explore and develop.To realize economic exploration and development of lacustri...Compared with marine facies shale strata,lacustrine shale strata are more complicated in geological conditions,and thus more difficult to explore and develop.To realize economic exploration and development of lacustrine shale oil,the geological regularities of accumulation and high yield of retained movable petroleum in shale should be understood first.In this work,taking the shale strata of Kong 2 Member and Sha 3 Member in the Paleogene of Huanghua depression in the Bohai Bay Basin as examples,based on the previous joint analysis results of over ten thousand core samples and the latest oil testing,production test and geochemical data of more than 30 horizontal wells,accumulation conditions and models of retained movable petroleum in lacustrine shale were studied comprehensively.The study shows that at moderate organic matter abundance(with TOC from 2%to 4%),shale strata have the best match between oil content and brittleness,and thus are rich in oil and good in fracability.Moderate ancient lake basin size and moderate sediment supply intensity are the internal factors leading to best coupling of organic matter abundance and brittle mineral content in the shale formation.Moderate thermal evolution maturity of Ro of 0.7%–1.0%(at burial depth of 3200 to 4300 m)is the interval where oil generation from thermal evolution and oil adsorption by kerogen in shale layers match best,and retained movable petroleum is high in proportion.Moderate diagenetic evolution stage(3200 to 4300 m in the middle diagenetic stage A)is conducive to the formation of a large number of dissolved pores and organic matter pores,which provide storage space for shale oil enrichment.Moderate development degree of natural fractures(without damaging the shale oil roof and floor sealing conditions)is conducive to the storage,seepage and preservation of shale oil.The research results have overthrown the general understanding that high organic matter abundance,high maturity,and high development degree of natural fractures are conducive to shale oil enrichment,and have guided the comprehensive evaluation of shale oil and gas sweet spots and well deployment in the second member of the Kongdian Formation in the Cangdong sag and the Shahejie Formation in the Qikou sag.Industrial development of the shale oil in Kong 2 Member of the Cangdong sag has made major breakthrough,and important signs of shale oil have been found in Sha 3 Member of the Qikou sag,demonstrating huge exploration potential of lacustrine shale oil.展开更多
基金The Key Program and General Program of the National Natural Science Foundation of China under contract Nos 40532011 and 40406010COMRA’s 11th Five Year Program under contract No. DYXM115-02-4-04the Natural Science Foundation of Guangdong Province under contract No.04300822
文摘Samples of sediments and the overlying water were collected in the Qi＇ao Island coastal zone,the Zhujiang（Pearl River） Estuary（ZE）.Denitrification rates,sediment oxygen demand（SOD）,and fluxes of inorganic nitrogen compounds were investigated with N2 flux method,using a self-designed continuous flow through and auto-sampling system.The results indicate that the denitrification rates varied between 222 and 908 μmol/（m2·h） with an average of 499 μmol /（m2·h）.During incubation,the sediments absorbed dissolved oxygen in the overlying water with SOD ranging from 300 to 2 363 μmol/（m2·h）.The denitrification rates were highly correlated with the SOD（r2=0.77） regardless of the NO-3＋NO-2 concentrations in the overlying water,organic carbon contents in sediments and water temperature,suggesting that the SOD was probably the main environmental factor controlling the denitrification in the Qi＇ao Island coastal zone.There was a net flux of NO-3＋NO-2 into the sediments from the overlying water.The NH＋4 flux from sediments into water as the result of mineralization was between 12.3 and 210.3 μmol/（m2·h）,which seems limited by both organic carbon content in sediment and dissolved oxygen concentration in the overlying water.
基金Supported by the PetroChina Science and Technology Major Project(2019E-2601,2018E-11)
文摘Compared with marine facies shale strata,lacustrine shale strata are more complicated in geological conditions,and thus more difficult to explore and develop.To realize economic exploration and development of lacustrine shale oil,the geological regularities of accumulation and high yield of retained movable petroleum in shale should be understood first.In this work,taking the shale strata of Kong 2 Member and Sha 3 Member in the Paleogene of Huanghua depression in the Bohai Bay Basin as examples,based on the previous joint analysis results of over ten thousand core samples and the latest oil testing,production test and geochemical data of more than 30 horizontal wells,accumulation conditions and models of retained movable petroleum in lacustrine shale were studied comprehensively.The study shows that at moderate organic matter abundance(with TOC from 2%to 4%),shale strata have the best match between oil content and brittleness,and thus are rich in oil and good in fracability.Moderate ancient lake basin size and moderate sediment supply intensity are the internal factors leading to best coupling of organic matter abundance and brittle mineral content in the shale formation.Moderate thermal evolution maturity of Ro of 0.7%–1.0%(at burial depth of 3200 to 4300 m)is the interval where oil generation from thermal evolution and oil adsorption by kerogen in shale layers match best,and retained movable petroleum is high in proportion.Moderate diagenetic evolution stage(3200 to 4300 m in the middle diagenetic stage A)is conducive to the formation of a large number of dissolved pores and organic matter pores,which provide storage space for shale oil enrichment.Moderate development degree of natural fractures(without damaging the shale oil roof and floor sealing conditions)is conducive to the storage,seepage and preservation of shale oil.The research results have overthrown the general understanding that high organic matter abundance,high maturity,and high development degree of natural fractures are conducive to shale oil enrichment,and have guided the comprehensive evaluation of shale oil and gas sweet spots and well deployment in the second member of the Kongdian Formation in the Cangdong sag and the Shahejie Formation in the Qikou sag.Industrial development of the shale oil in Kong 2 Member of the Cangdong sag has made major breakthrough,and important signs of shale oil have been found in Sha 3 Member of the Qikou sag,demonstrating huge exploration potential of lacustrine shale oil.
文摘针对现有的图像修复方法在面对大规模图像缺损和不规则破损区域修复时,修复结果出现生成结构与原图像语义不符以及纹理细节模糊等问题,本文提出一种利用生成边缘图的多尺度特征融合图像修复算法——MSFGAN(multi-scale feature network model based on edge condition).模型采用两阶段网络设计,使用边缘图作为修复条件对修复结果进行结构约束.首先,使用Canny算子提取待修复图像的边缘图进行完整边缘图生成;然后利用完整的边缘图结合待修复图像进行图像修复.为了弥补图像修复算法中经常出现的问题,提出一种融入了注意力机制的多尺度特征融合模块(attention mechanism multi-fusion convolution block,AM block),实现受损图像的特征提取和特征融合.在图像修复网络解码器部分引入跳跃链接,将高级语义提取和底层特征进行融合实现高质量细节纹理修复.在CelebA和Places2数据集上的测试结果显示,MSFGAN修复质量上比当前修复方法有一定提升,其中在20%–30%掩码比例中,SSIM平均提升0.0291,PSNR提升1.535 dB,使用消融实验验证了当前优化和创新点在图像修复任务中的有效性.
